Harbor



Nov. 25, 1924- 1,516,624

D. P. THOMPSON APPARATUS FOR HEATING ROLLS OF ROLLING MILLS Filed May 13 1922 3 Sheets-Sheet 1 Nov. 25, 1924. 1,516,624

D. P. THOMPSON APPARATUS FOR HEATING ROLLS OF ROLLING MILLS Filed May 13, 1922 3 Sheets-Sheet 2 ,j zy 2.

17206717077 flamti 171%027z Jon D. P. THOMPSON APPARATUS FOR HEATING ROLLS OF ROLLING MILLS 3 Sheets-Sheet 5 Filed May 13 Patented Nov. 25, 1924.

UNITED STATES DAVID P. THOMPSON, OF CHICAGO, ILLINOIS, ASSIGNO'R TO INLAND STEEL COMPANY, 4

PATENT OFFICE.

OF INDIANA HARBOR, INDIANA, A CORPORATION OF DELAWARE APPARATUS FOR HEATING ROLLS OF ROLLING MILLS.

Application filed May 13, 1922.

T 0 all whom it ,may concern.

Be it known that I, DAvm P. THOMPSON, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a new and useful Improvement in Apparatus for Heating Rolls of Rolling Mills, of which the following is a specification.

My invention relates, more particularly to the rolling of metal sheets involvin the rolling of the sheets from heated s eetforming bars by pawing them through relatively large solid rolls commonly constructed of chilled gray iron. I

The common practice in the rolling of sheets is to heat the rolls to the desired temperature for rolling the desired greater widths of sheets of relatively thin gage, by first passing between the rolls -a highly heated sheet-forming bar of a relatively short length and thereafter, in succession, passing between the rolls bars of greater lengths, until the rolls have been heated-to the desired degree for the rolling of bars of the length for producing the desired relatively wide sheets the rolls bein heated by the friction produced between t em and {)he bars and by the heat radiated from the ars.

The practice above stated has many disadvantages among which are that itre' quires a relatively great length of =time to heat the rolls for the rolling of wide sheets of thin gage. The sheets rolled from the bars of the shorter lengths are of -much less value than those rolled from the longer lengths due to their narrow widths and relatively heavy gage; the rolls oftentimes become fractured during this heating operation, and particularly upon the first application of heat thereto, due to the existence of foundry strains in the rolls; and the surfaces of the rolls are soon impaired, by the' heating upv of the same as above stated, for the proper rolling of the sheets. My object, generally stated, is to overcome the disadvantages of prior practices and especially those above enumerated particularly with a view to reducing the cost of rolling sheets and increasing the capacity of the rolls for rolling, during the period of time in which the rolls are in operation, the wider sheets of narrow gage.

Referring to the accompanying drawings:

Serial No. 560,543.

Figure is a view in front elevation of a rolling m1ll equipped with means for preliminarily heating the rolls in accordance with my invention and suitable. for practicing my improved process. Figure 2 is a section taken at the irregular. line 2-2 on Fig. 1 and viewed in the direction of the arrows. Figure 3 is a broken enlarged sectional view taken at the line 3-3 on" Fig. l and viewed in the direction of the arrows. Figure 4 is an enlarged plan sectional view taken at the line 14 on Fig. 2 and viewed in the direction of the arrows. Figure -5 is a plan sectional view taken at the line 5- -5 on Fig. 2 and viewed in'the direction ofthe arrows. Figure 6 is a face View of one of the plurality of electrical heating units employed, with certain portionsthereof broken away to disclose interior details. Figure 7 is :a section taken at thezline 7-7 on Fig. 6 and viewed in the direction of the arrows; and Figure S a section taken at the line 8 on Fig. 6 and viewed in the direction of the arrows.

In accordance with myiinvention I preliminarily heat, to the desired temperature, by electric current, the pairof cooperating rolls to be used for rolling the sheets throughout their cross section andsubstantially throughout the length of the main body portions of the rolls, the rolls being heated preferably to a temperature of about 300 F. at their peripheries at a point midway between their ends, thereby to cause these rolls to be conditioned for properly rolling sheets of relatively great width and thin gage.

In the drawings the invention is shown as applied to a rolling mill of common construction and involving generally stated a framework affording the uprights 9 spaced apart in which the necks 10 of the tworolls 11 one of which superposes the other, are journaled, the ends of the rolls 11 being adapted for connection therewith of Wabblers through the medium of which these rolls are driven. It may be here stated that according to common practice the lower roll is of true cylindrical form, and the periphcry of that portion of the upper roll which is contacted by the sheet-formingbars in the rolling operation, is circumferentially slightly concaved in order that these rolls shall properly function to produce sheets of uniform thickness throughout their extent, after the rolls have become properly heated.

The features of the specific construction selected for the purpose of illustrating my invention which features are shown and described but not claimed herein, are the invention of Robert L. h lclntosh and are shown and claimed in his copending application Serial No. 562,552, filed on even date with the present application.

The particular construction of means illustrated for preliminarily heating the rolls comprises a housing for application to the pair of rolls, which is provided with a series of electrical heating elements positioned to contact with substantially the entire peripheries of the portions of the rolls between the necks thereof. The housing-shown is formed of two simi ar sections 12 adapted .to be applied to the rolls from opposite sides thereof and be secured in place thereon. Each section is shown as formed of the elements 13, Hand 15 in the form of angle-bars spaced apart lengthwise of the rolls, the upper ends of the elements 13, 14 and 15, as to each section, being connected with a plate 16 and the lower ends with a plate 17, the plates 16 and 17 containing apertures, certain of which open through the margins of the plates, for receiving bolts 18 through the medium of which the housing sections are releasably secured in position on the rolls. The lower ends of the elements 13 and 15 are provided with legs 19 in which a shaft 20, carrying a roller 21. is mounted. and the upper ends olt' the elements 13 and 15 are provided with upwardly extending handleportions 22. Each of the housing sections 12 also comprises a member, represented at 23, of sheet like form. this member being preferably of flexible sheet-metal and contoured to substantially conform to the contour of the portions of the peripheries of the rollers which it opposes as shown in Fig. 2. Each member 23 is preferably rigidly secured. as by riveting, or otherwise. to those portions ot' the angle-shaped elements 13. 1 1 and 15 which parallel the rolls. at theupper and lower portions of the members 23. but are preferably disconuected from the said elements at those portions thereof between horizontal planes passing through the centers of the rolls.

The electrical heating elements forming a portion of each of the sections 12. and shown as of the common space-heater type, are represented at 2-1. These heating elements, which are interposed between the rolls and the members 23, contact with the peripheries of the rolls as represented in Fig. 2 and are grouped in any desirable arrangement. as for example that shown wherein they extend in a direction lengtlr wise of the rolls and in spaced relation to each other. Each heating element 24 is provided at opposite ends with angle-shaped brackets 25 which extend through openings 23 in the member 23, these brackets serving as terminals for the heating elements and through the medium of which these elements are electrically connected together in series, or in parallel, as desired, and with any suitable source of current supply. In the particular arrangement shown all of the brackets 25 at one end of the heating device are connected with one of the main line current wires and all of the brackets at the other end are connected with the other of the mainline current wires.

Each of the heating elements 24 is shown as comprising a metal casing 26, containing a coil of any suitable electrical resistance wire 27 extending substantially the full -lengthof'the element and wound about a core 28 of mica, or any other suitable insulating material, there being interposed between the bottom wall 29 of the casing 26 and the coil 27 a sheet 30 of insulatingmaterial, as for example mica. A strip of metal 31 directly underlies the'upperiwall portion 32 of the casing 26 and has interposed between itand the coil.27 a sheet 33 of insulating material as for example mica. Each element 24 is provided at each end with an eyelet 34 which flatwise bears at a shoulder-portion 35 thereof against the insulating strip 30 and extends through openings in the strips 31 and 33 and cut-out portions 36 in the upper portions 32 of the 'casing 26," these eyelets also extending through metal washers '37 and through openings in the base portions of the brackets 25. A mica washer 38 extends between each washer 37 and the iron strip 31, and the openings through the strip 31 are such size that the walls thereof are out of contact with the eyelets 34. Each eyelet 34 being in electrical contact with the adjacent bracket 25, is in electrical contact with one of the terminals of the coil 27.

In the particular construction illustrated means are provided whereby the sheet portions 23'may be bent into such form that the heat-in; elements 24 will contact with the peripheries of the rolls throughout substantially their entire extent as shown in Fig. 2. these means comprising a U-bar 39 which extends at its cross-bar portion 40 against. the outer surface of the sheet 23 and in a plane parallel with the axes of the rolls. the outer ends of the arms of the yoke 39. and represented at 41, being threaded and extending through openings in a channelhar 42 secured to. and extending crosswise of. the members 13, 14 and 15, the threaded ends of the arms -11 being provided with pairs of nuts 43 by means of which the de lll) sired pressure may be exerted and maintained against the sheeting 2 through the yokes 39 for deforming these sheets into the desired shape as above stated. it being uir derstood that after these sheets have on e been deformed by adjusting the yokes 3 as stated to adapt them to rolls of a particular size. no further adjustment is requiredv In the use of the apparatus shown the sections 12 are applied to opposite sides ol" the as sembled rolls to the position shown in Fig. 2. the provision of the rollers 21 and the handle portions 22 serving to permit these sections to be wheeled to the position for application to the rolls. after the manner of a wheelbarrow. lVith the sections 12 in place on the rolls and the desired circuit connections made for supplying current to the various heater elements 24. the current is permitted to pass through these elements. the heat g nerated thereby radiating into the rolls until the rolls are heated to the desired degree. as for example the temperature above specified. It has been found by actual demonstration that the rolls even when of the largest di mensions commonly used in rollingmill practice, may be heated to a degree snttieient for the starting in of the rolling of relatively Wide sheets of thin gage. and that such heating may be effected in a relativelji' short length of time. Thus the many dis advantages resulting from prior practices and above pointed out are eliminated, and great economy of structure and in the operation of mills, is effected.

It has also been found in the actual practice of the invention that the heating up of the rolls in accordance with the invention. as explained. almost entirely eliminates the danger of fracturing the rolls during the initial heating up of the same. from foundry strains therein. the heating of the rolls as stated, and which it will be understood involves a relatively gentle application of heat. as compared with the heating of the rolls by forcing heat into the latter from the relatively highly heated bars by friction of the bars therewith and by heat radiated there from. appearing to produce an action on the rolls in the nature of annealing.

It will be understood that the preliminary heating of the rolls as stated may be eftected either when the rolls are assembled with the other parts of the mill, or when disassembled therefrom. as for example while supported in racks from which they may be removed, for assembly with the other parts of the mill. after the preliminary heating. Thus a mill may be continuously operated. for the production of wide, narrow gage, sheets. except for such interruptions as result from the mere changing of rolls, as the preheating of the rolls makes possible the continued production of such sheets, without requiring the rolling of narrow, heavy gage, sheets, as is necessary where the substituted rolls are assembled, in cold condition. with the other parts of the mill.

ll hile I have described a certain particular apparatus embodying my invention, and by which my improved method may be practiced. l do not wish to be understood as intending to limit it thereto as the structure may be variously modified and altered without departing from the spirit of the invention. and the improved method practiced by emploving other apparatus.

lVhat I claim as new. and desire to secure b Letters Patent, is:

1. Apparatus for heating rolls of rolling mills. said apparatus comprising a sheet like member adapted to be positioned at the pe riphery of a roll. electrical heating elements positioned upon the sheet, like member for heating the rolls and means adapted for positioning the sheet like member adjacent the roll.

2. Apparatus for h iating rolls of rolling mills, said apparatus comprising a sheet like member adapted to be positioned at the periphery of a roll and to conform approXi mately to the roll contour. electrical heating elements positioned upon the sheet like memher for heating the rolls and means adapted for positioning the sheet like member adjacent the roll.

Apparatus for heating rolls of rolling mills, said apparatus comprising a heat in sulated blanket element adapted to be positioned about the periphery of the rolls and electrical heating elements upon the inner face of the blanket element and adapted to heat the roll.

4. Apparatus for heating rolls of rolling mills, said apparatus comprising a heat insulated blanket element adapted to be positioned about the periphery of the rolls and electrical heating elements upon the inner face of the blanket element and adapted to engage the roll surface to heat the roll.

DAVID P. THOlVIPSON 

